Abstract: One of the critical factors related to the success rate of in vitro fertilization-embryo transfer (IVF-ET) was the oocytes and embryos, with moderate number and high quality, obtained by the controlled ovarian stimulation (COS) protocol of which effect mainly depended on the ovarian response to gonadotropin (Gn). The ovarian response was affected by a variety of factors，including patient′s age，antral follicles counnt（AFC），basal level of follicle stimulating hormone，serum levels of anti-Mullerian hormone（AMH）and inhibin B. It is benefit to develop individual strategy of COH treatment to predict accurately the ovarian response before COS.

Key words: Ovary, Ovulation induction, Fertilization in vitro, Embryo transfer